Converter.



s'. B. FRUMKIN.

CONVERTER.

APPLICATION FILED SEPT. 6, 1911.

Patented'May 7,1912.

3 BEEETBAHBET 1.

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wbzesses 1' S. B. FRUMKIN.

CONVERTER.

APPLICATION FILED SEPT. e,

Patented May 7, 1912.

' 3 SHEETS-SHEET 2.

s. B. FRUMKIN.

CONVERTER.

APPLICATION FILED SEPT. 6, 1911.

3 W m 7 s W M u mu .2 t w a k M W llllll HI I' a P UNITED STATES PATENT OFFICE.

SROL BORUCHOW FRUMKIN, OF MINSK, RUSSIA.

CONVERTER.

To all whom it may concern:

Be it known that I, SRoL BORUCI-IOW FRUMKIN, a subject of the Emperor of Bussia, residing at Minsk, in the Empire of Russia, have invented a new and useful Converter, of which the following is a speci fication.

' This invention has for its object an improvement in an apparatus for turning pigiron into malleable iron, the apparatus being suitable both for roasting ores and for reducing iron ores directly to iron.

In the accompanying drawings Figure 1 illustrates the iron barrel of the apparatus with its trunnions 70 M, Fig. 2 is a vertical section through the barrel on the line AA.

in Fig. 1, Fig. 3 is a plan view of the whole apparatus, Fig. 4 is a vertical section through the apparatus on the line P-P in Fig. 8 and shows the refractory lining, Fig. 5 is a horizontal section through the line BB in Fig. 4, Fig. 6 is a side view of the apparatus and shows the openings 9 and s, Fig. 7 is a side view on a reduced scale of the apparatus on standards and in connection wit-h the heat regenerator, which serves for heating the blast-air introduced into the apparatus, and Fig. 8 is a horizontal longitudinal section through the regenerator. The nozzle 6 is disposed in the opening .8 and communicates with the air supply tube at through the sliding tube a, which is operated by means of the handle U.

The iron frame of the apparatus (Figs. 1 and 2) consists of two pairs of rings a a (one above and one below) of angle-iron and of an inner pair of rings Z) Z) of flat iron; to these rings are riveted the radially disposed cross rings 0 c, which hold fast the rings a a and I) b and form with them a rigid annular frame. In the spaces between the rings 0, this frame is covered on all sides by means of sheet iron plates cl (Figs. 3, 4, 5 and 6), which are bolted to the rings a and b, the screw-threads being cut into these rings. Then the lining of the apparatus with refractory material is commenced, for which purpose the outer sides of the annular frame are temporarily left uncovered, in other words they are not yet covered with the iron plates. In the outer wall of Specification of Letters Patent.

Application filed September 6, 1911.

Patented May '7, 1912. Serial No. 647,970.

the lining or brickwork two openings 9 and s are left. For lining the outer wall of the annular frame consisting of the parts a, b

and c a plate cl is screwed on beside the neck opening 9 and the lining is a plied to its inside, after which the next ollowing plate d With the pertaining lining is put on, and the work is in this manner continued, until the mantle of the apparatus is finished. The partition N (Figs. 4 and presses the gases downward on the metal bath and thus intensifies the process of oxidation, also it sets the metal in the apparatus to move in a circle.

The trunnions for tilting the apparatus are cast in one with the plates h, and the latter are fastened to the radially placed rings 0 c, which in turn are connected with one another by means of struts h 77. By means of the trunnions the apparatus is made to turn in the standards Z at right angles to its axis (Fig. 7). In Fig. 7 the dotted lines indicate the position of the ap paratus during the introduction of the pigiron or during the discharge of the finished molten metal.

The blast-air enters the apparatus through the nozzle e and the fire gases leave the apparatus through the opening 9. The nozzle 6 and the inlet mouth 8 consist of iron and are covered with clay to protect them .from the action of the fire. hen damaged, the nozzle and the door can be easily exchanged for new ones.

Near one of the trunnions h an opening may be disposed, through which the progress of the process can be observed, independently of the observation of the fire gases escaping from the opening g.

Operation of the apparatus.After properly heating the apparatus and after the introduction of the pig-iron to be treated therein, the apparatus is turned into a horizontal position and the sliding tube 2 is pushed into the nozzle 6, whereupon the blast is turned on, so that the air leaves the nozzle 6 through the opening 2' (Fig. 5), flows around the entire periphery of the apparatus, and acts upon the surface of the molten metal, While the fire gases escape from the apparatus through the opening 9, as is indicated by arrows in Fig. 5. During this process the pig-iron is turned into malleable lron or steel.

By the above described construction of the apparatus and its operation the following essential advantages are obtained:

1.The blast is directed toward the surface of the metal bath, whereby the loss of iron is avoided, which in the Bessemer process is caused by the spurting out of the iron from the retort into the atmosphere.

2.Under the action of the blast upon the surface of metal the gases developed from the metal bath are burned, so that carbonic oxid is turned into carbonic acid, whereby the temperature of both the bath and the working space is increased.

3.The fire gases act upon the surface of the metal bath for an incomparably longer time than in the Bessemer process, whereby the utilization of heat is perfected and the oxidizing effect upon the admixtures of the iron is intensified.

4.Owing to the absence of carbonic oxid and the great percentage of carbonic acid in the fire gases coming into contact with the molten metal, the sulfur (and also other admixtures) having passed into the slag is rendered unable to reduce and to return to the iron, which is the case in the Bessemer process owing to the presence of carbonic oxid, so that it remains bound to the slag, even when acid lining is employed.

5.Owing to the strong heating of the vault and the walls above the metal bath during the process it is possible after the termination of the process to turn the apparatus through an angle of 180, so that the metal flows to the glowing lining and can be left alone for a certain time, the openings being closed. Then the gases (CO, H and N) absorbed by the metal during the process will separate, whereby the metal becomes more dense and the porousness of the castings is reduced. At the same time also the process of extracting the protoxid of iron is finished, this extraction being effected automatically owing to the high temperature, even without any flux, provided that a small excess of carbon be left in the metal. Vida the passage in the work of Ledebur, volume III, page 267, edition by W. Erikson, 1899, which passage when translated reads as follows: The reduction of FeO by means of the carbon contained in the metal bath could only take place, if the metal could be kept in its liquid state for a longer time and be deprived of the possibility of reabsorbing oxygen. By allowing the product to stand for a sufliciently long time it is possible to obtain by means of this apparatus steel perfectly free from bubbles which steel in its quality is not inferior to crucible steel. Vz'de the passage in Ledebur, volume III,

page 267, which in translation reads as follows: Martin steel (sometimes also Bessel mer steel) is poured into the crucibles after i an addition of ferromanganese and is then allowed to stand in the crucible furnace. The oxids again forming have time to separate from the metal, exactly the same as the gases previously dissolved. Thereby the steel is improved.

6.Finally with this apparatus all costs for the construction and disposition of airchambers and twyers, such as are used in Bessemer converters, are saved. Also the outlay for the blast-engine is considerably smaller, since a comparatively small pressure only is required.

From the above it will be seen, that with this apparatus the heat developed during the process is fully utilized, so that for this reason cheap pig-iron can be used for the transformation, which pig-iron contains a sufficient percentage of silicium (Si) or phosphorus (P), that are required for obtaining the corresponding temperature in the metal bath. If it is desired to produce a still higher temperature in the apparatus for treating pig-iron with a minimum percentage of silicium or phosphorus, it. is possible to employ hot air for the blast, which air is heated in the regenerator invented by me and described below.

The regenerator consists of a system of iron tubes 1 r (Fig. 8) of about 50 millimeters diameter, the ends of which are fastened in boxes at m of which the rear box m is connected with the air supply tube a and the front box 777. with the tube 25. The front bent end t thereof carries the sliding tube 2, by means of which the connection with and the disconnection from the nozzle 0 can be effected. Through the mouth 2' of the nozzle the blast-air is made to enter.

The tube system r with its boxes on m and also the tube 2? are inclosed in the tubular mantle M M (Figs. 7 and 8), which on the side facing the apparatus terminates in a funnel-shaped widening X. At the other with the chimney Q.

lVhen the apparatus is in working order, the tube .2 communicates with the nozzle 0 and the fire-sheaf emanating from the opening g projects into the funnel X and the tubular mantle M M and is conducted to the other mantle end M under the sucking effect of the chimney Q and from the said end it passes through Q into the atmosphere. During their path the fire gases flow along and heat the'tube t, the boxes on m and the tube battery 1 which in turn transmit the heat received to the cold blast-air passing through them. In this manner the fire gases in this regenerator are directed oppositely to the blast-air heated by them, as is indicated by the arrows in Fig. 8, so that the heat is utilized to its maximum.

end the mantle M is closed and is provided When the process is finished and the blast is turned off, the tube a is withdrawn from the nozzle 6, and then the apparatus can be turned on its trunnions for the discharge or the like, as is indicated by dotted lines in Fig. 7.

Where so preferred, the regenerator may be set at rest and the apparatus alone may be used, in which case the tube a is pushed directly over the end of the air-supply tube a, as is shown at Figs. 3, at and 5.

The novel apparatus is employed not only for turning'pig-iron into welding iron and steel, but also for other metallurgical operations, such as for example roasting and reducing ores, etc.

The study of the requirements for roasting sulfurous ores has shown, that for the complete roasting and for the complete extraction of the sulfur from the ores the following conditions must be fulfilled: 1, a high temperature; 2, an oxidizing gas, and, 3, for the gases a free access from all sides to the several pieces of ore. With the known ore roasting furnaces these conditions are as a rule not fulfilled, but by the apparatus according to my invention all the requirements for the roasting are satisfied, as is evident from the above description of the construction and operation of the apparatus. In fact this is quite true, for in my apparatus the ore is distributed in a very thin layer, so that the several pieces of ore can not exert upon one another any pressure worth mentioning, but loosely bear on one another and consequently present a quite free access to the gases. The coal is disposed in the apparatus exclusively close to the supply of blast-air separately from the ore, so that as the air is obliged to pass first through the layer of coal its oxygen combines with the carbon to form carbonic acid (CO which gas then passes through the whole channel of the apparatus while flowing between the several pieces of ore until it escapes through the opening g. Owing to the free access to the several pieces of ore and to the effect of the blast the uniformity of the oxidizing action of the carbonic acid extends over the entire surface of the ores, and when in roasting the ores crack, the gas will under the pressure of the blast penetrate through the crevices formed and continue its oxidizing and loosening work in the interior of the ores, while at the same time an energetic separation of sulfur takes place.

The products of decomposition of the sulfuric and arsenic combinations are carried away with the blast. Moreover by reason of the loose bedding of the pieces of ore in the apparatus the particles of slag forming on the surface of the ores will be carried off by the blast, so that the pieces of ore are prevented from caking together, such as is the case in shaft-furnaces. IVith the apparatus according to my invention therefore a complete separation of the sulfur and also of a great part of the remaining objection able admixtures can be obtained.

In the regenerator a dust-catcher may be inserted in the current of fire gases in order to collect the dust, that is the sand particles of the dead lode. As also iron oxids may get mixed with the dust, the collected dustmay be passed over a magnet without the regenerator for recovering the iron oxids. The heat of the gases escaping from the apparatus during the ore roasting can also be utilized, if the gases leaving the regenerator are not passed through the chimney Q, into the atmosphere, in the manner that the gases are passed into the furnace of the steam boiler for the blast-engine or into a kiln on which the chimney Q, is disposed.

The reduction 0 the ores-At the end of the roasting process we have a completely heated working space of the apparatus and the cleaned and heated ore possessing a temperature, at which the iron can be easily re duced from the iron oxid (Fe O by means of carbon. Under these circumstances it is sufficient for the reduction of the ore to iron to supply a larger quantity of coal to the apparatus through the opening 9 for the blast, when the carbon of the coal will reduce the iron oxids to iron. As to the fireproof dead lode and to other minerals, they in their state of softening (loosening of their combinations) will be carried off by the blast in the shape of dust and sand particles, at the same time also the ash in proportion to the burning coal will be discharged, so that in the apparatus a bath of molten metal without slag is obtained. In this manner welding iron and steel can also be obtained directly from ores by means of the new apparatus. Then on the comple tion of the process the bath of metal is to be enriched with carbon, it is only necessary to introduce charcoal into the apparatus and to close the openings, when the carbon of the charcoal will be absorbed by the molten metal. In order to accelerate this process, the metal may be mixed with the charcoal by turning the apparatus several times on its trunnions 7c is through an angle of 180. Of course, where so preferred, also manganese or silicium ores may be added together with the coal or separately whereupon the ores are easily reduced to manganese and silicium, which then pass into the metal. In this respect the new apparatus actually presents an enormous advantage over the stack furnaces, since in the latter the circumstaifbes are not so favorable for the reduction of manganese and silicium ores.

When in the new apparatus the ores are roasted and reduced in the above described manner, it is possible to obtain iron perfectly free from sulfur even without the employment of any lime.

' in the ambient air the tube X should be pushed close to the opening 9 and may moreover be tightened by means of a strip of asbestos fabric. Then it will be possible to pass the carbonic oxid from the regenerator to, the steam boiler furnace, etc., where it can be burned.

hen the blast is kept turned on and no coal is added, the oxygen of the supplied air will oxidize the admixtures of the pig-iron, so that welding iron or steel is obtained in the apparatus. The high temperature necessary for maintaining the liquid condition of the iron is obtained by the combustion of the admixtures of pig-iron and of a part of the iron to Fe O while the forming iron oxid is discharged from the apparatus by means of the blast. Then the heat for the reduction of Fe O to iron will be saved.

From the above explanations it will 'be seen, that by the roasting and the reduction in the new apparatus the following advantages are obtained: 1. The freeing of the ores from objectionable admixtures. 2. Saving of heat stored up in the heated ores and apparatus. 3. Saving in combustible, which for example in stack furnaces is Wasted for melting the refractory lode and the fluxes. f. Saving of time spent over burning the coke added and melting the dead lode. 5. Saving in steam power for driving the blastengine, which for my apparatus can be replaced by a sufficiently powerful ventilator, since in the new apparatus the blast need hardly overcome any resistance excepting the friction in the tubes.

I claim:

1. An apparatus of the character described, comprising an annular recipient adapted to be partly filled with the charge to be treated, means for pivotally suspending the recipient at right angles to its axis,

and means for introducing an air blast into said recipient above the level of the charge so as to sweep over the surface thereof.

2. An apparatus of the character described, comprisinoan annular recipient adapted to be part T filled with the charge to be treated, means for pivotally suspending the recipient at rightangles to its axis whereby said recipient may be completely reversed, and means for introducing an air blast into said recipient above the level of the charge so as to sweep over the surface thereof.

8. An apparatus of the character described, comprising an annular recipient adapted to be partly filled with the charge to be treated, a pair of diametrically (lisposed trunnions extending at right angles to the axis of said recipient, bearings supporting said trunnions whereby the recipient may be freely rotated at rightangles to its axis, and means for introducing an air blast into said recipient above the level of the charge so as to sweep over the surface thereof.

4. An apparatus of the character described, comprising a rotatable annular rccipient adapted to be partly filled with the material to be treated, said recipient being provided with an air ingress opening and a gas egress opening, a nozzle entering the ingress opening and adapted to send an air blast through the recipient and over said material, air preheating tubes communicating with the nozzle, and a mantle surrounding said tubes and arranged opposite the gas egress opening, whereby the gas leaving said opening is forced to flow through said mantle.

SROL BORUCHOXV FRUMKIN.

Witnesses A. FRUMKIN, BERNARD HUsE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

